A combination of the AstraZeneca, Pfizer and Moderna vaccines produced a positive immune response to COVID-19 in a U.K. study, according to Reuters (subscription).
The goal: The major British study was developed with the aim of demonstrating that receiving different varieties of COVID-19 vaccines did not necessarily mean weaker protection.
The science: A study conducted among 1,070 volunteer patients found that administering the AstraZeneca–Oxford vaccine followed by the Moderna or Novavax shots produced higher antibodies and T-cell responses than two shots of the AstraZeneca vaccine. Pfizer followed by Moderna was favorable to a standard two-shot Pfizer course. No major safety concerns were raised.
The benefits: The results of the study could have a range of favorable implications. If a mix and match approach is effective, middle- and lower-income countries need not worry about combining vaccines if supplies are running low, making vaccine programs more efficient. It may also influence approaches to immunization against new variants, like delta and omicron, and non-coronaviral diseases.
- “We’re showing…you don’t have to stick rigidly to receiving the same vaccine for a second dose…and that if the programme will be delivered more quickly by using multiple vaccines, then it is okay to do so,” said Oxford Professor Matthew Snape, who led the trial.
Meanwhile, a three-shot course of the Pfizer vaccine is able to neutralize the new omicron variant based on new laboratory findings, reports (subscription) Reuters. Two vaccine doses also resulted in significantly lower neutralizing antibodies.
The last word: “Ensuring as many people as possible are fully vaccinated with the first two dose series and a booster remains the best course of action to prevent the spread of COVID-19,” said Pfizer Chairman and CEO Albert Bourla.